1. Field of the Invention
The invention relates to a guiding assembly for a high-voltage circuit-breaker having an insulating operating rod which extends coaxially with clearance inside a hollow support insulator in several superimposed sections to transmit the operating movement from an operating mechanism from the earth potential area to the high voltage potential area where the breaking poles, notably of the arc puffer type, are located, said rod being slide-mounted and guided by at least one guiding insulator extending transversely between the rod and the support insulator at the level where two successive sections of the support insulator are joined.
2. Description of the prior art
High-voltage circuit-breakers, in particular the puffer type, require a large amount of operating energy to move the contacts quickly and to compress the dielectric puffer gas by means of the piston-and-cylinder device. This operating energy is transmitted by a mechanical insulating rod connecting the high potential area with an area close to earth in which the operating mechanism, for example a hydraulic operating mechanism, is located. The circuit-breaker pole(s), or arc chutes, are supported by an insulator post the height of which varies according to the circuit-breaker voltage and can reach several meters. The insulating rod is mounted inside this support insulator post which also constitutes a duct to deliver the dielectric gas to the arc chutes. This insulating rod of great length is capable of transmitting high traction forces used to operate circuit-breaker opening which requires the greatest amount of energy. The closing operation, on the other hand, which is commanded by an operating rod compression force, is limited by the risks of this rod buckling. To avoid this buckling, notably during fast closing of the contacts, a means has already been proposed of guiding the operating rod inside the support insulator by fitting intermediate guiding parts at intervals along this insulator. In a porcelain support insulator in several superimposed sections joined together by metallic flanges in the form of clamps, an intermediate part is inserted between successive metallic clamps. This assembly method, which gives total satisfaction, requires very small manufacturing tolerances especially for the intermediate part in cast insulating material and the clearance between the porcelain of two successive support sections. It also requires sealing and centering rings which increase the cost of manufacture and assembly.
The object of the present invention is to enable an operating rod guiding assembly inside the support insulator to be produced using simple means with high tolerances.